Signal transducer and activator of transcription 3 (STAT3) is a member of the STAT family of transcription factors that replicates and transmits signals from cell surface receptors to the nucleus.175 The continuous activation of STAT3 is often associated with the poor prognosis of human cancer because the activated STAT3 signal can not only promote the growth, survival, and metastasis of tumor cells but also inhibit the antitumor immune response.176 Therefore, STAT3 is an attractive target for the treatment of human cancer and other human diseases. Here, STAT3 is linked to cancer.